European legal systems now recognize that an electronic document whose author is identifiable in a secure manner and which is kept under conditions that allow its integrity to be guaranteed has the same probative value as a written hardcopy document (Article 1316 and following of the French Civil Code, for example). However, the most widely-used systems for production, such as a word processor generating a document in the PDF (Portable Digital File) format, and for exchange (electronic messaging over the Internet) of electronic documents do not currently allow either the identity of their author or their integrity to be guaranteed. The problem relates to both private correspondences between individuals or between an individual and a business or an institution and the correspondences between businesses and administrations or between a business or an administration and its customers or its users. In the latter case, the flow of documents can be particularly high (several tens of millions of invoices per month are addressed to the customers of EDF, of GDF Suez, of Orange). The fabrication and the dispatching of these documents are therefore automated in production chains which necessarily involve many operators. If it is desired to guarantee that the document sent and archived is identical to that originally produced, it is therefore necessary to provide a traceability from end to end of all these operations and a verification that the operators have carried out the operations that they needed to execute. This applies to a production chain for both paper documents and electronic documents. Furthermore, in the case of an electronic transmission, in order for the documents thus sent to be considered as being validly addressed, these documents need to carry the identification of the sender and the latter needs to be assured of the identity of the addressees.
Partial solutions have been applied to the problem of the probative value of electronic documents exchanged via electronic channels. In particular, if the sender disposes of an electronic signature certificate delivered under prescribed conditions and whose validity is verified by a certification authority, his identity as author of an electronic document on which he will have displayed said certificate will be recognized as validly demonstrated. However, electronic signature certificates are still not very common by reason notably of their high cost and of their inconvenience of use.
The Applicant has therefore already filed patent applications in France notably with the aim of providing a rating on the identity of a sender and of addressees of electronic documents allowing the probative value of the documents exchanged between these parties to be judged. See for example the Applications filed under the numbers FR/06 04 107 and FR/08 02 239. In addition, the Applicant is filing, on the same day as the present application, a patent application whose object is to mainly deal with the problem of the certification of all the attributes of the users of the secure electronic correspondence system by a mechanism of sessions and the certification of the correspondences exchanged by a mechanism of certification tokens.
In order to further improve the reliability of the scheduling and execution processes for the secure electronic correspondences within a context of industrial production processing hundreds of thousands or even millions of documents per day, it has however turned out to be necessary to be able to guarantee the quality and the conservation of documents referred to as ‘originals’ thanks to a process of copy authentication of versions traced by certification tokens.